Modified double gauss objective



SR 1 v April 7, 1970 HQQGLAND ET AL 3,504,961

MODIFIED DOUBLE GAUSS OBJECTIVE Filed April 1, 1968 I l E\ 9 F H [I I INVENTORS. J'rm 1700f Zanc? [Z145 Beiensig United States Patent 3,504,961 MODIFIED DOUBLE GAUSS OBJECTIVE Jan Hoogland, Wilton, and Ellis I. Betensky, Ridgefield, Conn., assignors to The Perkin-Elmer Corporation, Norwalk, Conn., a corporation of New York Filed Apr. 1, 1968, Ser. No. 717,763 Int. Cl. G02b 9/62, 9/64, 11/34 US. Cl. 350-214 ABSTRACT OF THE DISCLOSURE A modified double Gauss type objective having five components is further modified by adding a sixth component. This sixth component is a relatively thick meniscus element having radii that are about equal, is convex to the front and is positioned behind the fifth component.

This invention relates to optical objectives. More particularly, this invention relates to an optical objective of the modified double Gauss type for use in photography, microphotography, image converter tube applications and other similar purposes.

The double Gauss objective is a well-known type of optical objective of which the standard or norm consists of four components, the outer two being positive and the inner two being meniscus shaped negative components concave toward a central air space in which an aperture stop is mounted, at least one component on each side of the central airspace being compound for achromatizing the image. This standard type has been modified in various ways such as by splitting one or both of the positive components into two positive components each, by making more than two of the components compound, by introducing a small airspace into one or more of the components, or in other ways.

The following is a list of some of the printed publications on optical objectives pertinent to this invention: US. Patents 2,683,398; 2,701,982; 2,836,102; 2,846,923; 2,896,506; and 3,049,975.

It is an object of this invention to provide a new and improved optical objective.

It is another object of this invention to provide a new and improved optical objective.

It is another object of this invention to provide a new and improved optical objective of the double Gauss type.

It is still another object of this invention to provide a new and improved optical objective of large numerical aperture with high modulation transfer function at relatively low spatial frequencies over moderate field angles.

' It is yet still another object of this invention to provide a new and improved Optical objective of medium numerical aperture with high modulation transfer function at high spatial frequencies over moderate field angles. It is a further object of this invention to provide a new and improved optical objective having thermostability of monochromatic aberrations, color aberrations as well as focal position over a temperature range of at least 200 F.

It is another object of this invention to provide a double Gauss type optical objective that is well corrected for all monochromatic and color aberrations at a relative aperture of at least up to about F/.9 and over a field of about 30 degrees.

The above and other objects are achieved by constructing an optical objective according to this invention.

Briefly, the objective is a six component, eight element modified double Gauss type objective in which the first component is a positive element having a convex surface 4 Claims convex to the front, the second component is a single positive meniscus concave toward a central airspace, the third and fourth components are meniscus shaped doublets, consisting of a positive and a negative element located on either side of and concave toward the central airspace, and the fifth component is a positive bioconvex element. As to these first five is somewhat similar to known versions of the modified double Gauss type objective. The sixth component is a single, meniscus shaped component with radii that are about equal, is relatively thick and is convex toward the central airspace. The sixth component not only functions as a field flattener, but also corrects for spherical aberration, coma, etc. The objective may be mounted in a stainless steel support to achieve thermostability. In one embodiment of the invention, the objective is made up as described above. In another embodiment, two identical objectives as described above are symmetrically arranged in series. One feature of the invention is the provision of the sixth component.

A clearer concept of the scope of the invention along with other advantages and features thereof will be obtained from the following detailed description taken in conjunction with the drawings, and the novel features will be particularly pointed out hereinafter in the appended claims.

In the drawings:

FIGURE 1 is an optical diagram of one embodiment of the invention; and

FIGURE 2 is an optical diagram of another embodiment of the invention.

Referring now to FIGURE 1, there is shown an embodiment of an optical objective constructed according to this invention. The objective comprises six components containing eight elements and is particularly suited for although not exclusively limited to image converter tube applications.

The first component (I) (starting from the front or object side) is a positive element A and has a convex surface that is convex to the front. The second component (II) is a positive meniscus element B and is convex to the front. The third component (III) is a negative meniscus shaped doublet, convex to the front and made up of a positive element C and a negative element D. The fourth component (IV) is a negative meniscus shaped doublet, concave to the front and made up of a negative element E and a positive element F. The fifth component (V) is a positive double convex element G. The sixth component (VI) is a relatively thick meniscus shaped element H, convex to the front and having radii that are about equal. The thickness of this sixth component (VI) is about between .18 and .45 times the effective focal length of the objective. The two radii of the sixth component (VI) differ in size by no more than a factor of about 1.5.

The objective may further include a window W positioned behind the sixth component (VI). The objective is mounted on a stainless steel supporting frame 12. The following table shows the constructional data for one example of an optical objective constructed according to the embodiment shown in FIGURE 1 without the window W. In the table, the components are designated by Roman numerals in ascending order from the front of the objective to the rear, with the light assumed to come from the front. The elements are designated by capital letters. The curvature of a surface is marked plus or minus depending on whether it is convex or concave, respectively, toward the incoming light. As is well known in the art, the curvatureof a surface is equal to the reciprocal of its radius.

TABLE I Focal Length-=L0000 Relative Aperture=f/1.0 Total Field of View=24 Front Vertex Distance=1.6000 Back Focal Length- .1000 Stop Position=.1064 after rear surface of element D Thickness Index of Abbe Component Element Curvature or Spacing Refraction, n No., v

C1=.8476 I A t =.1420 1. 64304 60.10

S1=.0050 All :1.2594 II B l2=.1420 1. 64304 60. 10

Sz=.0050 Air C5=l.8126 C h=.2450 1. 64304 60. III Cg=.225fi 8312454 Air Ca=1.9682 E t =.0400 1. 64062 35. 34 IV C =2.1671

F tu=.2000 1. 7480 44. 77

C o=-l.2190

Si=.0247 Air Cu=.fi277 V G t =.1039 1.80688 46. 76

St=.0Ol0 Air Cn=1.3435 VI H b12969 1. 80688 46.76

The following table shows the constructional data for another example of an optical objective constructed according to the embodiment shown in FIGURE 1. In this example, the window W is included.

TABLE II Focal Lengtli=1.0053

Total Field of View=24 Front Vertex Distance:1.6064 Back Focal Length=.0006 Stop Posltion=.1399 after element D Relative Aperture=f/0.95

Thickness Index of Abbe No., Component Element Curvature or Spacing Refraction, 'n c v C1=. 7632 I A ti=. 1460 1. 61997 60. 33

S 0150 Air C l. 2820 II B tz=. 1351 1. 61997 60. 33

S1=. 0166 All C =l. 8376 C ta=. 2431 1. 63992 60. 10 III O=. 2589 Sa=. 2630 Air Ca= 1. 9289 E t 0400 1. 63637 35. 34 IV .c C9=2. 1277 F t|=. 1999 l. 743 57 44. 77

Cio== 1. 2390 S4=. 0053 Air C 8666 V G t1=. 0980 1. 67008 47.11

S 0042 Air Cia=l. 3571 VI H t 2039 1. 67008 47. 11

85 0970 Air C1s=0. 0000 W to=. 0087 1. 45852 67. 25

Referring now to FIGURE 2, there is shown another embodiment of the invention. The objective comprises twelve components containing sixteen elements and is especially suited for although not exclusively limited to microphotography applications. Basically, the objective is made up of two identical objectives of the type similar to that shown in FIGURE 1, symmetrically arranged about a central stop with the long conjugate side of each ob jective facing the stop.

Thus, starting from the front, the first component (1;)

meniscus shaped doublet, convex to the front and made up of a positive element L and a negative element M. The fourth component (1V is a negative meniscus shaped doublet, concave to the front and made up of a negative element N and a positive element 0. The fifth component (V is a positive meniscus element P concave to the front. The sixth component (V1 is a positive element Q having a convex surface convex to the rear. Components (VH through (XII are identical to components (V1 through (I respectively, however, each component is TABLE III Object Distance=25.000 Relative Aperture=f/2.5 Back Focal Length=25.000 Stop Position=0.5000 alter element S Object to Image Distnnce=800.001

6 (c) a negative meniscus component (I11 concave the rear; (d) a negative meniscus component (IV concave to the front;

(e) a positive meniscus component (V convex to the rear; (f) a positive component (VI having a convex surface convex to the rear;

Component Element Curvature Thickness Index of Re- Abbe or Spacing fraction, 'n No., v

Ca1=-8.8713X10- 1 .T t31=76.0000 1. 68804 46. 39

S =6.9615 Air c33=1.4609X10' 11 K l3a=20.0000 1. 68804 46. 39

Ca4= -tl.il3l42 10- S3g= 20.0740 All Ca5=4.00l4 10-= L ta:=29.3579 1. 76507 44. 08

Ca ---8.6012 (10- I11 Saa= .2000 Air Ca1= 8.7081X10" M ta4== 15.0000 1. 65963 33. 51

Czs=8.00l2 (10- Sa4=73.6333 Air C3e= -1.3640) 10' N ia5= 15.0000 1. 72940 27. 78

C4n= 3.8035X10- I IV Sa5= 0. 0000 All C4|= 3.5706X10- 0 tar-57.6511 1. 63313 62. 27

Ssa= 1.0000 Air C4s= 3.1545X10- V P ta1=20.0000 1. 63313 62. 27

Sa1= 13.6224 All C45=4.9672X10' VI Q taa=-0000 1. 63313 62.27

C4s= -3.3676X10' S 1.0000 Air C4:=1*l.3676 10- VII R tao=20-0000 1. 63313 62. 27

C4a= 4.9672X10 S:a=13.6224 All Cn=4.4520Xl0- VIII; S 4u=20-0000 1. 63313 62. 27

Cso=3.1545X10" S4o= 1.0000 Air C51=7.10l3Xl0' T t4 =57 .6511 1. 63313 62. 27

Cn= 3.6706X10' IX S41=6.0000 Ail C5:=3.8035X10 U tn= 15.0000 1. 72940 27. 78

Ct4=1.3540X10" Su=73.6333 Air C5s= 8.0012X10- V t4s= 15.0000 1. 65963 33. 51

C.u=8.7081) 10- X, Sn= .2000 Air C51=8.60l2X10- W tn=29.3579 1. 76507 44. 08

S4 =20.0740 Air C5v= 6.3342X10 XI, X t4s=20.0000 1. 68804 46.

Ceu= l..4609) 10- S4 6.9615 Air Co 6.3375X10- XII Y t4e=76.0000 1. 68804 46. 30

Cez=8.8713X10 Although this invention has been described with respect to specific embodiments thereof, it is understood that these are not to be considered as limiting the invention set forth in the appended claims.

What is claimed is:

1. An optical objective especially suited for use in microphotography comprising from the front to the rear:

(a) a relatively thick meniscus component (1 concave to the front and having radii that are about equal;

(b) a double convex component (I1 (g) a positive meniscus component (VII convex to the front;

(h) a positive meniscus component (VIII convex to the front;

(i) a negative meniscus component (1X concave to the rear;

(j) a negative meniscus component (X concave to the from;

(k) a double convex component (XI and (l) a relatively thick meniscus component (XII convex to the front and having radii that are about equal.

2. The objective aCCOl'dlDg to claim 1 and charactera negatlve memscus component (III) concave to ized by the followlng constructlonal data: the rear;

TABLE III Object Distance=25.000 Object to Image Distanco=800.001 Relative A perture=f/2.5 Back Focal Length=25.000 Stop Posit1on=0.5000 after element S 7 Component Element Curvature Thickness Index of Re- Abbe or Spacing fraction, 11 No., v

C3 -8.8713X10' I; I ts1=76.0000 1. 68804 46. 39

Caz= 6.3375 (10- Sz 6.9615 Air Caa=1.4609 (10* 11 K m=2o.00o0 1. 68804 40. a9

Ca|= 6.3342X10 Saa= 20.0740 Air C:5=4.0614X10" L tas=29.3579 1. 76507 44 08 Cal= 8.6012X III; S33=.2000 All Ca7= -8-7081X10 M tt4=15.0000 I. 65963 33. 51

Cas=8.0012X10- Sa4=73.6333 Air C3 1.3640X10' N ta5=15.0000 1. 72940 27. 78 I C4n= --3.s035x10 v s..=0. 0000 Air C 3.5706X10- O tae=57.6511 1. 63313 62. 27

C g=7.1013X10- Sz0=1.0000 Air C43==3.1545X10' V P ta1=20.0000 1. 63313 62. 27 C 4.45Z0X10' Sz7=13.6224 Air C45=4.9672X10' VI; Q tn=20.0000 1. 63313 62. 27

S=L0000 Ail C47=3.3676X10 VII; R taq=20.0000 1. 63313 62. 27

O4s= 4.9672X10- S5g==13.6224 Air C4g=4.1520 10' VIII S t 20.0000 1. 63313 62. 27

C5u=3.1545X10' S4q= 1.0000 A11 C51=7.1013X10' T t4 =57.6511 1. 63313 62. 27

Csz=3.5700X10- IX; Sn=6.0000 Air C53=3.8035X10' U iu= 15.0000 1. 72940 27. 73

. Su=73.6333 Air C55= -8.0012X10- V t4a=15.0000 1. 65963 33. 51

Cu=8-7081X10' X S43=.2000 Air C57=8.6012X10" W tu=29.3579 1. 76507 44. 08

C5g= 4.0614X10- S44=20.0740 A1! C5n=6.3342X10- XI X m=20.0000 1. 68804 46. 39

S =6.9615 A1! Cu=6.3375X10- X11 Y t |=76.0000 1. 68804 46. 39

Cu=8.8713X10' 3. An optical objective comprising from the front to (d) a negative meniscus component (IV) concave to the rear: the front;

(a) a positive component (I) having a convex surface (e) a bioconvex component (V);

convex to the front; (f) a relatively thick meniscus component (VI) con- (b) a positive meniscus component (II) convex to the vex to the front and having radii that are about front; equal; and

(g) said components being characterized by the 1501- (c) a negative memscus component (III) concave to lowing constructional data: the rear;

TABLE I Focal Length=1.0000 Relative Aperture =f/1.0 Total Field of View=24 Front Vertex Distance=,l.6000 Back Focal Length=.1000 Stop Position=.1064 after rear surface of element D Component Element Curvature Thickness Index of Abbe. No.,

or Spacing Refraction, n v

C1=.8476 I A t;=.1420 1. 64304 60.10

S =.0050 All Ca=1.2594 II B tz=.1420 1. 64304 60.10

Sz=.0050 All C5=L8l26 C ta=.2450 1. 64304 60. 10 III Ca=.2256

s;=.2454 Air C =1.9682 E t .0400 1. 64062 35. 34 IV C9=2.1671

S =.0247 All C11=.6277 V G t =.1039 1. 80688 46. 76

S =.0010 Air Ci:=1.3435 VI H ta=.2969 1. 80688 46. 76

4. An optical objective comprising from the front to the rear:

(a) a positive component (I) having a convex surface 35 convex to the front; (b) a positive meniscus component (II) convex to the front;

TABLE II Focal Length=1.0053

Total Field of View=24 Front Vertex Distance=1.6064 Back Focal Length=.0006 Stop Posit1on:.1399 after element D Relative Aperture=f/0.95

Component Element Curvature Thickness Index of Abbe. No.,

or Spacing Refraction, n v

C 7632 I A t 1460 1. 61997 60. 33

Si=. 0150 Air C =1. 2820 Il B l2=. 1351 1. 61997 60. 33

S2=. 0166 Air C 1. 8376 C ia=. 2431 1. 63992 60. 10 III 0 2589 Sa=. 2630 Air Ca= -1. 9289 E t 0400 1. 63637 35. 34 IV Co=2. 1277 F tt=. 1999 1. 74357 44. 77

S4=. 0053 Air 011 8666 V .r G t1=. 0980 1 67008 47. 11

Ciz= 4748 S5=. 0042 All Cn=1. 3571 ta=. 2939 1 67008 47. 11 VI H CH=1. 5182 S 0970 Air C =0. 0000 W o=- 0087 1. 45852 67. 25

(References on following page) 11 12 References Cited JOHN K. CORBIN, Primary Examiner UNITED STATES PATENTS US Cl. X.R 2,828,671 4/1958 Murakami 350-215 350-215 FOREIGN PATENTS 5 22,079 10/1964 Japan. 

